LEAK TEST HELP TO CHECK INVISSIBLE HOLE IN A VESSELA flow of gas or liquid through the wall of a vessel is called leak. Leak testing is the process use to detect manufacturing defects which helps to verify the integrity of products and improve consumer safety. Leak detector serves to determine if, and in some cases where a leak has occurred within a system that contains liquid or gas. Detectors can also serve larger applications pipelines. Other application of leak detectors equipment include power generation, research and development, testing coating and analytical instruments, automotive packages and sensor, inspection maintenance of vacuum system. Leak detector may also be able to detect helium, oxygen, argon, CO2 and other gases. Pipe lines network are the most economic mode of transportation for oil, gases and other fluid products. As a means of long distance transport. Pipelines have to fulfill high demands or safety, reliability and efficiency. If properly maintained, pipelines can last indefinitely without leaks. If a pipeline is not properly maintained, it can corrode particularly on construction joints. Most significant leak that does occur is cause by damage from nearby excavation, low points where moisture collects or locations with imperfections in the pipe. However these defects can be identified by inspection tools and corrected before they progress to a leak. Other reasons for leaks include accidents, earth movement or sabotage.